Safety switch



`May 2, 195 H. J. HAMMERLY SAFETY SWITCH 5 Sheets-Sheet l Filed sept. 25, 1946 4@ 45 JNVENTOR.

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www Igan May 2, 1950 H. J. HAMMERLY SAFETY SWITCH 3 Sheets-Sheet 3 Flled Sep?l 25\ 1946 5. 75

NSULAT/ON INVENTOR. HERMAN/I. HAMMEELY Patented May K2l, 195.0

4.sArvEfrY SWITCH Herman J. Hammerly, Plainville, Conn., assigner to The Trumbull ElectrcrManufaturing 'Come man?, Blainville, Conn, a corporation of Collnecticut Application September 25, 1946,'SerialNo. 699,150

My Vinvention relates to electric-:switches of. the enciosedersafety type in which theswitching mechanism ris mounted kin za box and provided with an -Vactuating memberoutside yof the box.

iThe main obj ect is vto provide a simple and compactfand'yetfecientswitch of the llow :price field.

Withth-at linmin'd,v I have provided la box with alhin'ged cover in-which1is mountedaninsulating basewhich carries thecircuit .terminaisthe protective-devices,vthe'switchfcontacts and the contact making and breakingrotor. 'Thefouter end oi' the actuating member carried bythe insulating`base`projects through the :cover 'and is provided 'with means for sealing -the joint between the cover andthe actuatorand for llocking the switch.

The proposed yform of'the invention is shownin the 'accompanying-'drawings :and will be described in the Afollowingspecification.

Fig. 1 "is `a front view of #an 'enclosed lswitch embodying one form of my 'invention and-indicating in Ldotted lines the outline of the Ainterior switch base.

Fig. 2 is 1an end view 'of the switch box and showing the 'actuatinghandlemember.

Fig. 3 isa `front view vof -afragment .of the vvcover and showing the actuating handle member on a larger scale.

Fig -4 lis a cross sectional -view of the actuating handle shaft taken on the plane-of the '1ine4--f4l` of F155.

F1gf`5^is Vavertical sectional l'view and elevation vshowingffthe shari-,rand af-ragmen'tiof the supportv ing parts.

Fig. i'is fa' plan view: of `the base V.with :attached partsona scaleiarger'fthanthatfofrFigl1.

Figi?" islaivertical-fsectional view'on the `plane 'o'f'fthe'line `l-"| `ofl'F-ig. 6 and showing the switch rotor 1in'- thev closed 1 circuit zposition.

yFig. \8 -is va.- sectional view voi a lfragment-'of the base-'on theiplanexofthe line ,-8-'8 of Fig. 6 and showinglthe relation of-fa load circuit-terminaland the fconneeted fuse .terminals .and Switch 1 contact.

lFiguSwis:asectional-view 4of la fragmentof the base on the p1ane1of the line ;.9.-.9of ,'Eig. .6 and showing-the :relation offa line .,circuititerminal and a switch ycontactanii vfuse terminal.

It?ig..:10 iis;a:l;iottom planview ,ofthe base with thexiittachedl line terminals .and :the switch rotor in :the @closed circuit o position.

lig. 11iisfaiplaneviewbf the rotor withfits c011- tants.

(Cl. 20D-155) Fig. 13 is a bottom plan Vview of the rotor with its contacts.

Fig. 14 is a plan VView showing a modification of theswitch base and parts vfor cartridge type fuse protection.

The box body I5 may be of any suitable vform and provided with a cover I5 which is preferably hinged at l1.

Theswitching mechanism mounted Within the box is all carried by .an insulating base I8 which is adapted `to be secured-tothe bottom of the box many-suitable manner as for instance by .a Screw (not shown) through the passage |9 in the base.

Line terminals 20, `2li are secured to opposite corners ofthe base at vthe Lipper edge and load terminals 2|, 2| are secured to the base at opposite corners of .the lower edge of the base. Each line terminal has a spring yf :ontact arm extension 22'at the rear held in place for instance by a screw or ystud `23. The form of deviceshown in Figs. 'Gand 7 is intended to .carry .protective devices in the -form of fuse yplugs (not shown) and for this purpose a screw-'threaded fuse socket 24 is lmounted on -each side of the base and secured to a-n'extension `25 `of -theloajd terminal by lmeans .of'screwsor-studs 2 6. lThe center contact 2l ier-.eachfusefplugA is vpreferably the Afor-rn of a serrated-stud iforced'throngh the base so that its lower `end `constitutes one of the switch contacts. When a fuse-plug lisscrewedintoy its socket it prevents the center stud from Working loose.

A switch rotor28 :has `auhub 29 .and `is rotatably mounted lin-.thelovver .endfof atubular or hollow post 30. This rotor .carries tyvo contact buttons 3|, 3|. Each buttonisdropped into a hole 32 in the rocker .and preventedirom Yfalling out hyengagement of adjacent pants. .The rocker is kalso provided with :two shallow recesses E33, j33. The underside of the base is provided with an arcuate track `34 `for guiding one of the `contact buttons. This `track is provided Vwidthtransverse grooves so vas vto vinterr u p t'the *surface of the track .and avoid the possibility ofmetal Yparticles v,forming a ,conductoralongthe'track. The .free .end of each of the spring armcontacts2z2 is provided with a boss 36 lin.f1lignmen t 4with the `adjacent .contact stud 21. The rotorfisprovided vitfithan .inclined cam surface 3l' -at each end which extends yloertween the frecess ,33 .and the adjacent Contact button 3|. Each .cam. surface terminates in ran abrupt shoulder 38 adjacent thezcontact button so that as Vthe rotor is -turnedbetween the jbase and the 1305565.36, .36 of the contact arms the contact arms will 'be placed under tension and .then snapped onto the .Contact .buttons thus .irwlieating clearly to the operator that the circuit has been closed. In breaking the circuit, the bosses 36, 36 drop into the recesses 33 and thus indicate that the switch has been turned to the fully oi position.

The rotor is preferably provided with flanges 39, 39 which are interposed between the contacts and the operating shaft. The rotation of the rotor is limited by the opposite sides of an abutment 40. (Fig. 10.)

The switch 'is actuated by a shaft 4l which is preferably formed from a single stamping of sheet metal and has a handle 42. This shaft has a bearing washer 43 mounted on the upper end of the post 36 and the shaft has a limited longitudinal movement through the washer. The lower end of the shaft passes through a slot 44 in the rotor and is upset or spread at 45 to hold the parts together, A washer t5 is preferably provided to form a seat for the end of the shaft. The upper end of the shaft is provided with a washer il which has a boss which ts within an opening d8 in the cover. The washer is secured to the shaft and handle member by the lugs 49 which are integral with the upper end of the shaft. A spring G mounted on the shaft 4l is interposed between the lugs 4Q and the washer i3 so as to exert a tens-ion on the shaft and thus draw the rotor and its hub upward in the bottom of the post 3i! when the box cover is open and also when the switch unit is removed from the box. The shaft has a shoulder 5l which coacts with the washer 43 to limit the downward movement of the shaft.

To provide a convenient means for locking the switch either in the on or off position, I have provided a lug 52 which may be integral with the cover and projects upwardly therefrom at the periphery of the opening 38. A latch 53 is pivoted at 54 to the handle member 42. This pivot is eccentric to the axis of the shaft so that the latch may be thrown into the full line position of Fig. 5 to limit the rotation of the handle and shaft or thrown into the dotted line position which prevents the latch from engaging the stop lug 52. The shaft handle may be provided with an opening55 to accommodatev a 4pad lock' or other form of locking device (not shown).

The switch may be provided with a neutral terminal 56 and also provided with an insulating back plate 5l if desired.

The form of construction shown in Fig. 14 is designed to accommodate cartridge type fuses instead of the fuse plugs previously mentioned. For this purpose, fuse clips 6) and 6! are provided in place of the screw-threaded sockets previously mentioned. Otherwise the mechanism and operation is essentially the same as 'that previously described.

The construction thus shown and described provides a contact switch in which cable or wire connections may be made without interference with the switchy operating mechanism. It leaves a clear wall space for cable entrance holes or knockouts in all four side walls of the box.

' The spring construction on the handle shaft eliminates any loose feeling of the parts although they are slidably connected. vThe spring also pushes the flange on the handle washer 4l into a snug seal with the inside of the cover when the'cover is closed. This prevents any accidental ash or lire through the handle hole in the cover should there be an explosion within the box.

The sliding connection of the handle'shait base and having also allows for manufacturing variations in the dimensions of the -box and the switch mechanism. rihe movable contacts oat or slide in the rotor and the handle shaft oats or slides in the rotor so that if the handle is depressed during cover closing or by accident, strain upon the resilient contacts will yb'e'.minmizedQ-andconnection of thecircuit through the switch will notbe interrupted.

Although I have shown the invention as applied to a 2- pole switch, it should be understood that various features are applicable to 3-pole and 4-pole switches.

The invention involving the switch and its relation to the housing is claimed in my application Serial Number 45,909 led August 24, 1948.

I claim:

l. An electric switch having a base, an actuating shaft rotatably mounted in said base, a twoarmed rotor mounted on the lower part of said shaft beneath said base, a contact loosely carried by each arm of said rotor, spring vcontact arms carried by said base, contacts mounted in the base in alinement with the ends ofV said arms, said base having tracks for said rotor contacts leading to the contacts in .the base, said rotor having cam faces inclined toward its contacts and terminating in shoulders at the edges ofthe Tre-f.I spective contacts Afor causing the spring contactv arms to snap from said shoulders to engage the base contacts when the rotor is turned.

2. An electric switch having a base, an actuating shaft rotatably mounted in said base, a twoarmed rotor mounted onfthe lower part of said shaft beneath said base, a contact looselycarlried by each arm of said rotor, said rotor having a recess in each arm spaced circumferentially from its contact, spring contact arms carried by said base having terminal bosses, contacts mounted in the base in alinement with said bosses, said base having tracks for said rotor contacts leading to the contacts in the base, said rotor having shoulders at the edges of the respective contacts for causing the bosses ofthe spring contact arms to snap from said shoulders. to engage the basecontacts when'the rotor, is

turned. n y l.

3. An electric switch having a basegan actuating shaft rotatably mounted in said base, a twoarmed rotor mounted on the lower part of said shaft beneath said base, a contact loosely carried by each arm of said rotor, said rotor having a recess in each arm spaced circumferentially from its contact, spring contact arms carried by said terminal bosses, contacts mounted in the base in alinement with said bosses, said base having tracks for said -rotcr` contacts leading/to the contacts in the `base, said tracks having grooves transverse to vthe direction of movement of said rotor contacts, said rotor having cam faces leading from its recesses and inclined toward its contacts and terminating in shoulders at the edges of the respective contacts for causing the bosses of the spring contact arms to snap from said shoulders to engage the base contacts when the rotor is turned. Y

4. In a switch construction, a base having fuse plug center contact studs extending through the base from front to rear, a fuse socket surrounding each stud the rear ends of said studs constituting switch contacts, spring switch arms secured at one end of each to the base and each having a free endextending directly beneath a switch l contact and a rotor supported'in the base having contact members and oscillated to bringsaid contact members between the ends of the switch arms and the respective switch contacts and a shaft for actuating the rotor.

5. In a switch construction, a base having fuse plug center contact studs extending through the base from front to back, a fuse socket surrounding each stud the rear ends constitutingvswitch contacts, switch arms secured at one end of each to the base and each having a free end extending directly beneath a switch contact anda rotor supported in the base having contact members and oscillated to bring said contact members between the ends of the switch arms and the respective switch contacts, said contact vmembers being loosely slidable axially in the roto'rfand a shaft foroscillating the rotor.

6. In a switch construction, a base having fuse plug center contact studs extending through the base from front to back, a fuse socket surrounding each stud the rear nds constituting switch contacts, spring switch arms secured aft one end of each to the base and each having alfree end extending directly beneath a switch contact and a rotor supported in the base having contact members and oscillated to bring said contact members between the ends of the switch arms and the respective switch contacts anda springpressed shaft for actuating the rotor movable longitudinally of the base and of the rotor.

7. In an electric switch, an insulatingbase having a tubular post integral therewith and projecting upwardly from the central part ofthe base and having a recess in the lower face of the base, an insulating rotor mounted in said recess and having contact buttons with upper and lower exposed contact surfaces, line terminal members secured to the base, each terminal member consisting of a strip of metal with a spring contact arm at the rear of the base extending into said recess and having a contact end pressing against said rotor in an open circuit position and against one of the contact buttons when rthe circuit is closed, fuse receiving means mounted on the front of the base at a side opposite the' line terminal members, each fuse receiving member having a contact at its rear in alinement with the springpressed contact end of one of the line terminal members, an actuating shaft extending through said post and connected at its inner y,end with said rotor, an abutment at the outer end-ofthe shaft, and a spring on said shaft betweenisaid post and said abutment for pressing said rotoitoward said base.

Number 8. In an electric switch, an insulating basehaving a tubular post integral therewith and projecting upwardly from the central part of the base and having a recess in the lower face of the base, an insulating rotor mounted in said recess and having contact buttons with upper and lower exposed contact surfaces, line terminal members secured to opposite sides of the base, each terminal member consisting of a single strip of metal extending around an edge of the base with a binding screw at the front of the baseand a spring contact arm at the rear of the base extending into said recess and having a contact end pressing against said rotor in an open circuit position and against one of the contact buttons when the circuit is closed, fuse receiving means mounted on the front of the base at a side opposite the binding screws of the line terminal members, each fuse receiving member having a contact at its rear in alinement with the springpressed contact end of one of the line terminal members and a binding screw at the front of the base, an actuating shaft extending through said post and connected at its inner end with said rotor, an abutment at the outer end of the shaft, and a spring on said shaft between said post and said abutment for pressing said rotor toward said base.

HERMAN J. HAMMERLY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,138,763 Klein May 11, 1915 1,217,566 Cavanagh Feb. 27, 1917 1,277,981 Mathers Sept. 3, 1918 1,683,231 Bayne Sept. 4, 1928 1,921,765 Meuer Aug. 8, 1933 1,965,099 Good July 3, 1934 1,975,247 Andres et al Oct. 2, 1934 2,115,069 Hall Apr. 26, 1938 2,224,848 Cole et al Dec. 17, 194D 2,418,616 Batcheller Apr. 8, 1947 2,421,881 Heasty June 10, 1947 2,454,540 Benander Nov. 23, 1948 FOREIGN PATENTS Number Country Date 113,440 Switzerland May 17, 1926 

